Well drilling tool



Sept.15, 1936. 1 H, HOWARD 2,054,255

WELL DRILLING TOOL Filed Nov. 15, 1934 H Trop/var 2/ el PE2 aav /2 Patented Sept. l5, 1936 I I UNITED STATES PATENT OFFICE WELL DRILLING TOOL John H. Howard, Huntington Park, Calif.

Application November 13, 1934, Serial No. 752,836

15 Claims. (Cl. Z55-61) This invention relates to a well tool and reis hammered by the spring pressed hammer memlates more particularly to a drilling tool for use ber when the core or earth formation offers subin the rotary method of well drilling. A general stantial resistance to its rotation.

object of this invention is to provide an improved A further object of the invention is to provide well drill that is particularly rapid and efficient in a well drill that is eiective in drilling in earth 5 its drilling action. formations of various characters. Y

It has been found that well drills which oper- The various objects and features of my invenate to drill an annular cut or channel in the tion will be fully understood from the following earth formation are much more rapid in their detailed description of a typical preferred form penetration of the formation than drills which and application of my invention, throughout l0 cut cylindrical or full open bores. The rst rnenwhich description reference is made to the actioned type of well drills heretofore have been of Companying drawing, in WhiChl limited practioability and usefulness because the Fig- 1 is a longitudinal detailed sectional view cores they leave in the wells usually have to be of a Well drill embodying the present invention i5 withdrawn at intervals or must be broken up 'or illustrating the Cere deStIOying Cutter in its 15 removed by speciai tools. The operations of relowermost position. Fig. 2 is a view similar to moving the cores and breaking up the cores are Fig. l illustrating the core engaging cutter in an expensive and time consuming. upper position. Fig. 3 is a bottom elevation of One of the objects of the present invention is the drill. Fig. 4 is a fragmentary Side elevation to provide a simple practical well drill that is of a portion of the hammer member and a por- 20 operable to rapidly and eniciently cut a comtion of the stem of the core engaging cutter illusparatively narrow channel in the earth formatrating the teeth in positions where they are tion and simultaneously with such action destroy about to trip or disengage and Fig. 5 is a transor cut away the core thus formed without maverse detailed sectional view taken as indicated l5 terially reducing the cutting speed or eiciency by line 5-5 on Fig. 1.

of the drill. The well drill of the present invention includes,

Another object of the invention is to provide generally, a body I0 having means Il at its lower a well drill of the character mentioned that inend for making an annular cut in the earth forcludes a core destroying cutter that is operable mation, a shiftable and relatively rotatable inner to cut away the core by a rotary cutting action cutter' I2 for destroying or cutting away the core 30 and to shatter or break up the core by aharnmerleft by the means il, and means i3 OI gOVerIiing or percussive action. The operation of the ing the movement or operation of the cutter I2. core destroying cutter of the drill depends to a The body I0 iS an elongate tubular structure large degree upon the character of the earth forfor carrying the means II and the cutter I2 and mation encountered. For example when the core for housing the means I3. The body IU may be 35 destroying cutter is acting on shale formation varied considerably in construction and design there is little resistance to its rotation and it Without departing from the Spirit 0f the inveneiiectively cuts away the core by rotation, and tion. In the particular case illustrated in the when the cutter is acting on coarse sand formadrawing the body IIl includes three sections,

tions or the like offering considerable resistance namely, an upper section I4, an intermediate 40 to its rotation the cutter is automatically opersection I5, and a lower section IB. vThe upper ated to break up the core by a percussive or section I4 of the body is provided with means for crushing action. connecting with a drilling string of drill pipe or Another object of the invention is to provide a the like. In the particular embodiment of the well drill of the character mentioned in which invention illustrated in the drawing this means 45 the core destroying cutter operates during the takes the form of a tapered screw-threaded pin usual rotation of the drill and its operation is Il on the upper end of the body section I4. The automatic, that is, it does not necessitate special pin I'I has a central longitudinal opening or pasrnanipulation or handling of the drilling string. sage I8 for conducting circulation fluid down- A further object of the invention is to provide wardly from the drilling string to the interior of 50 a well drill of the character mentioned that inthe body IIl. The middle or intermediate body cludes a novel toothed or cam connection between section I5 is threadedly connected with the lower the core destroying cutter and a spring pressed end 0f the upper Section i4 and With the upper hammer member whereby the cutter is rotated end of the lower section I5 being in the nature when there is little resistance to its rotation and of a sub. A pin I9 or its equivalent is provided on the lower end of the lower body section I6 to carry the cutting means II. The three body sections I4, I5 and I6 may be of uniform external diameter and may be of substantially the same internal diameter as illustrated in the drawing.

The cutting means II on the lower end of the body is operable to cut an annular channel in the earth formation and thus leave a core of the formation which is acted upon by the inner cutter I2. The cutting means II includes a tubular body or shoe 20 threaded on the pin I9. A plurality of circumferentially spaced cutting parts 2| is provided on the shoe 20. The cutting parts 2| may be in the form of substantially radial blades projecting downwardly from the shoe. The cutting blades 2| project outwardly from the shoe to make a cut sufficiently large in diameter to readily receive the body ID and project inwardly to form a core C that may pass into the body section I6 with suitable clearance. When the drill is rotated and fed downwardly in the usual manner the cutting blades 2| operate to cut or form an annular channel in the earth formation and where the earth formation is hard or relatively hard may' leave an upstanding core C which is acted upon by the inner cutter I2.

The inner cutter I2 is provided to cut away or destroy the core C of hard or relatively hard formation or to act on the formation at the center of the well bore when the drill is pene-- trating soft earth formations. In accordance with the invention the inner cutter I2 is arranged to shift longitudinally with respect to the body IU and to have rotary motion relative to the body. The inner cutter I2 is movable between a position where it projects below the cutting blades 2| and a positionwithin the body section I6 where it is spaced some distance above the blades 2|. The core engaging inner cutter I2 has cutting parts or blades 22 on its lower end. The cutting blades 22 are designed to be effective in cutting away the core when the cutter I2 rotates with the body II) and to shatter or break up the formation or core when the cutter I2 is hammered or acted upon by the means I3. In practice there may be four blades 22 radiating from the center of the lower face of the cutter I2. The active lower edges of the blades 22 are preferably inclined upwardly and outwardly so that the cutter is effective in breaking up the formation or core through a percussive or crushing action.

The inner cutter I2 is provided with a central upwardly projecting shank 23. The shank 23 may be connected with the cutter I 2 by a suitable threaded connection 24. The shank 23 is cylindrical or round in transverse cross section and is slidable and rotatable in the central opening 25 of a web 26. The web 26 extends transversely across the interior of the body section I6 and is spaced a considerable distance above the lower end of the section. An enlargement or head 21 is provided on the shank 23 above the web 26 and is adapted to cooperate with the web to limit'the downward movement of the cutter I2 relative to the body I0. When the head 21 is in engagement with the web 26 to stop the cutter I2 in its lowermostposition the blades 22 of the cutter may project beyond the blades 2i of the cutting means II as illustrated in Fig. l of the drawing. When the cutter I2 is in this position it may act on the formation at the bottom-of the well bore. The shank 23 operates in the opening 25 to support and guide the inner cutter I2 for rotative and longitudinal movement.

The means I3 is in the nature of a control means for the inner cutter I2 and under certain conditions of operation causes the inner cutter to turn with the body I0 to cut by a rotative action and under other operating conditions oper- 5 ates to impart a downward hammering to the cutter I2 whereby it shatters or breaks the formation through a percussive or crushing action. The means I3 includes a hammer member 28 shiftable longitudinally in the tubular body IIJ. 10

The hammer member 28 is splined or keyed to the body to slide therein and rotate therewith. In the preferred construction the hammer member 28 has spaced longitudinal keys or splines 29 slidable in keyways 30 in the inner wall of l5 the body section I5. Open or unoccupied keyways 3| are provided in the wall of the section I5 between the keyways 30 carrying the splines 29. The open keyways 3| fqrm fluid or circulation passages in the wall of the section I5. The ham- 20 mer member 28 is adapted to strike or hammer downwardly against the shank 23 and in the form of the invention illustrated in the drawing the hammer member 28 is provided in its lower end with a central socket 32 adapted to receive 25 an upstanding boss or anvil part 33 on the head 21. The side surface of the anvil part 30 has. suitable clearance with the side wall of the socket 32. The parts are proportioned so that the upper end wall 34 of the socket 32 is adapted to strike 30 the upper end of the anvil part 33 to impart a downward hammer blow to the anvil part 33 and the cutter I2 connected therewith. A port 35 is provided in the hammer member 28 to communicate with the upper end of the socket 32 to pro- 35 vide for the free escape of fluid trapped in the socket.

A central upwardly projecting stem 3B is provided on the hammer member 28. The stem 36 extends upwardly into the body section I4 and 40 is slidable in an opening 31 in a transverse web 38 in said body section. The stem 36 slidably operating in the opening 31 guides and centers the hammer member 28 in the body. A suitable block or cap 39 may be provided on the upper end of 45 the stem 31 to limit the downward movement of the hammer member 28 when the body sections are disconnected. The cap 39 has clearance with the web 38 when the parts are assembled as illustrated in the drawing and does not operate 5o to limit the movement of the hammer member 28. In accordance with the invention the hammer member 28 is spring urged or spring actuated. A spiralled or coiled spring 40 surrounds the stem 36 and is arranged under compression between 55 the upper end of the hammer member 28 and the web 38 to normally urge the hammer member downwardly. The spring 40 urges the hammer member downwardly to cooperate with the anvil part 33 and the head 21 and thus urges the cutter 60 I2 downwardly against the earth formation or core.

The means I3 includes a series of cam parts or teeth 4| on the lower end of the hammer part 28 to cooperate with complementary or meshing 65 cam-like'teeth 42 on the head 21. The teeth 4I and 42 are formed to transmit rotative movement from the hammer member 2B to the inner cutter I2 when there is little resistance to rotation of the cutter I2 and operate as cams to feed 70` I2 is acting on formation which materially resists 75 its rotation. The teeth 4| of the hammer member 28 have forward faces 43 inclined downwardly and rearwardly relative to the direction of rotation of the drill during operation. The rear sides or faces 44 of the teeth 4I may be axial or substantially vertical. The teeth 42 of the head 2I have axial or substantially vertical forward faces 45 and downwardly and rearwardly inclined rear faces 46, to cooperate with the correspondingly inclined faces |43 of the teeth 4 I. The points or outer ends of the teeth 4| and 42 may be suitably flattened. The parts are related so that the ends or points of the teeth 4I and 42 have clearance with the bottoms of the notches between the teeth when the face 34 is in contact with the upper end of the anvil part 33. With the parts related in this manner the teeth 4I and 42 are not subjected Ato excessive deforming impacts when the means I4 operates to impart hammering blows to the anvil part 33.

When there is relatively little resistance to rotation of the cutter I2 the teeth 4| and 42 remain in mesh to form a rotative drive or connection between the body IU and cutter I2. When the tool is operating in an earth formation which provides appreciable resistance to rotation of the cutter I2 the cutter I2 drags or lags and the inclined faces 43 of the teeth 4I slide upwardly on the inclined surfaces 46 of the teeth 42 to feed the hammer member 28 upwardly against the action of the spring 40 and thus store energy or force in the spring. Upon the ends vof the teeth 4| riding or passing over the ends of the teeth 42 the hammer member I2 is allowed to suddenly move downwardly with considerable force to impart a downward blow to the anvil part 33 to drive the cutter I2 into the core or earth formation. At this point it may be noted that the cooperating cam parts or teeth 4| and 42 operate to raise or move the hammer part 28 with. out raising the body I0 or its cutting means I I.

The invention includes means whereby the circulation fluid is discharged downwardly through the body I0 to aid in eroding the core and to maintain a proper circulation in the well bore. A plurality of spaced ports 48 is provided in the web 38 to pass the fluid downwardly into the lower portion of the body section I4. The key ways 3| of the section I5 conduct the circulation uid downwardly past or around the hammer member 28 into the upper portion of the body section I6. A plurality of vertical or longitudinal ports 49 is provided in the web 26 to discharge the circulation uid downwardly into the lower end portion of the body section I6. The fluid discharging from the ports 49 effectively washes or flushes the cutter I2, and when a core C is received in the lower end of the tool, this fluid may erode or wash away the formation of the core. When the drill is operating in soft earth formations the circulation uid discharging under pressure from the ports 49 may soften and erode the formation to such an extent that the cutter I2 under the pressure of the spring 4U may maintain a down position such as illustrated in Fig. 1 of the drawing.

In operation the tool or drill is connected with the lower end of a drilling string of drill pipe and is rotated and fed downwardly in the well in the usual manner. The blades 2| of the cutting means II operate tov cut an annular channel in the earth formation. Circulation iuid is continuously pumped downwardly through the drilling string and discharges from the ports 49 to now from the lower end of the drill and pass upwardly around the drill. The inner cutter or core destroying cutter I2 is yieldingly urged downwardly by the spring 4U to engage and act on the formation in the center of the well bore. When the drill is operating in earth formations such as shale, which do not offer excessive resistance torotationkof the cutting parts the cutter I2 may turn with the body I0 so that its cutting blades 22 cut away the formation or core through a dragging or rotative action. The teeth 4I cooperating with the teeth 42 transmit rotation from the splined hammer member 28 to the stem 23 to provide for the rotation of the cutter I2. In some instances the inner cutter I2 may maintain its lowermost position illustrated in Fig. l of the drawing while in other instances the inner cutter may be held upwardly with respect to the body IIJ and operate in a position such as illustrated in Fig. 2 of the drawing. It is to be noted that the teeth 4| and 42 remain in cooperation or engagement regardless of the longitudinal disposition of the inner cutter I2.

When the drill is operating in formations which oier excessive resistance to rotation of the cutting parts the inner cutter I2 may be held against rotation or may lag through its engagement with the upper end of the core C or with the earthl formation. When this occurs the forward inclined faces 43 of the teeth 4I shift upwardly on the faces 46 of the teeth 42 causing the hammer member 28 to move upwardly against the action of the spring 40. When a core C is present the cutter I2 may be in a position such as illustrated in Fig. 2 of the drawing and the spring 40 may be compressed to a substantial degree. The upward feeding of the hammer member 28 due to the cooperation 0f the teeth 4| and 42 further'k increases the compression strain on the spring 4U. Upon the surfaces or faces 43 of the teeth 4I moving out of engagement with the faces 46 the teeth 4| snap or trip over the upper ends of the teeth 42 and thus allow the hammer member. I2 to suddenly move downwardly under the action of the compressed spring 4D. The teeth 4I and 42 are again brought into mesh during this downward movement of the hammer member. The hammer member 28 is moved downwardly with considerable force and the wall 34 of its socket 32 is brought into hammering engagement with the upper end of the anvil part 33. This hammer action or blow is transmitted directly to the inner cutter I2 and the inner cutter shatters or breaks up the core C or formation. It will be apparent that downward hammering blows are successively transmitted to the inner cutter I2 as long as the formation offers appreciable or excessive resistance to its rotation.

The means I3 operates'to automatically impart downward hammering blows to the cutter I2 during the normal or usual rotation of the drill. 'Ihe downward feeding or drilling pressures on the drill may maintain the cutting means II in its proper cooperation with the earth formation and the blades 2| are not raised from the bottom of the bore when the hammer member 28 is moved upwardly and released to impart the hammering blows to the inner cutter I2. The operation of the core destroying inner cutter I2 is entirely automatic and the drill does not have to be reciprocated to break up the core by a percussive or hammering action. The operation of the inner cutter I2 depends upon the character of the formation being penetrated and the means I3 automatically governs its operation. The formation of the free upstanding core C is readily shattered and broken away by the downward blows of the inner cutter I2.l The cutting means Il is.v rapid and efficient in operation and its speed and eiiiciency are not appreciably aiected by the operation of the means I2. The drill of the present invention is particularly efficient and is capable of proper effective operation in earth formations of various characters.

Having described only a typical preferred form and application of my invention I do not wish to be limited or restricted to the specic forms and applications herein set forth, but wish to reserve to myself any modifications or variations that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. A well drill including a tubular body to be rigidly connected with a rotary drilling string, cutting means on the body for making an annular cut in the earth formation and leaving a corel for reception in the body, an inner cutter retractible into the body as the core is formed and proportioned to act only within said cut, and means operable by ,rotation of the body lor imparting hammer blows to the inner cutter to cut the core as the body rotates.

2. A well drill including a body to be rigidly connected with a drilling string and having an opening in its lower end, cutting means on the lower end f body for making an annular cut in the earth formation and leaving a core for reception by the opening, an inner cutter retractible into the body opening as the core is formed and adapted to act on the core, and cam means in the body for hammering the inner cutter as the body rotates.

3. A well drill for use on a rotary drilling string including, a body having an opening in its lower end, means for rigidly connecting the body with the drilling string, cutting means on the body for making an annular cut and leaving a core for reception by said opening, a cutter for acting on the core and shiftable relative to the body to move into the opening as the core formed, and cam means in the body causing the cutter to rotate with the body when there is little resistance to its rotation and for hammering the cutter when there is increased resistance to its rotation.

4. A well drill for use on a rotary drilling string including, a body, means for rigidly connecting the body with drilling string to be rotated thereby and moved vertically therewith, the body having an opening in its lower end, cutting means on the body for making an annular cut and leaving a core for reception -by said opening, a cutter proportioned to act only within the annular cut for acting on the core and shiftable relative to the body to move into the opening as the core is formed, and means urging the cutter downwardly relative to the body and operable by rotation of the drill to impart downward blows to the cutter.

5. A well drill for use on a rotary drilling string including, a body, means for rigidly connecting the body with the drilling string, the

` body having an opening in its lower end, cutting and rotatable therewith, and an operative cam connection between the cutter and member tending to cause the cutter to turn with the body and operable to impart downward blows to the cutter when it lags relative to the body.

6. A well drill for use on a rotary drilling st'ring including, a body, means for rigidly connecting the body with the drilling string, the body having an opening in its lower end; cutting means on the body for making an annular cut and leaving a core for reception by said opening, a cutter for acting on the core and shiftable relative to the body to move into the opening as the core is formed and received in the opening, a member shiftable in the body and rotatable therewith, yieldable means urging the member downwardly, and a rotative driving connecting between the member and cutter releasable whereby the yieldable means imparts blows to the cutter through the medium of the member.

'7. A well drill for use on a rotary drilling string including, a body, means-for rigidly connecting the body with the drilling string, the body having an opening in its lower end, cutting' means on the body for making an annular cut and leaving a core for reception by said opening, a cutter for acting on the core and shiftable relative to the body to move into the opening as the core is formed, a shiftable spring pressed member in the body rotatable therewith, and parts on the cutter and member for transmitting rotation from the member to the cutter and releasable whereby the member may give the cutter a downward blow.

8. A well drill for use on a rotary drilling string including, a body, means for rigidly connecting the body with the drilling string, the body having an opening in its lower end, cutting means on the body for making an annular cut and leaving a core for reception by said opening, a cutter for acting on the core and shiftable relative to the body to move into the opening as the core is formed and received in the opening, a member shitable in the body and rotatable therewith, yieldable means 'urging the member downwardly, and a rotative driving connection between the member and cutter including, a shank on the cutter shiftable in the opening, and cooperating cams on the member and shank operable to move the member upwardly and suddenly disengage when the cutter lags relative to the rotating body to allow the member to give the cutter a downward blow to cut away the core by precussion. L

9. A well drill including a body to be rigidly attached to a drilling string to be rotated thereby and move longitudinally therewith, the body having an opening in its lower end, cutting means on the lower end of the body adapted to make an annular cut and leave a core for reception by the opening, a reciprocable shank in the body, a cutter on the shank operable to act on the core and retractible into said opening, as the core is received in the opening, a spring pressed hammer member in the body rotatable therewith, and a torsion transmitting connection between the shank and hammer member releasable under a certain torque to cause an impact between the shank and member.

l0. A well drill including a body to be rigidly attached to a drilling string to be rotated thereby and to move longitudinally therewith, the body having an opening in its lower end, cutting means on the lower end of the body adapted to make an annular cut and leave a core for reception bythe opening, a reciprocable shank in the body, a. cutter on the shank operable to act cn the core and retractible into said opening, a spring pressed hammer member in the body rotatable therewith, and parts on the hammer member and shank adapted to cooperate for the transmission of torque, said parts having surfaces adapted to cooperate to force the hammer member upwardly and releasable to cause impact of the member against the shank.

11. A well drill including a body to be rigidly attached to a drilling string to be rotated thereby, the body having an opening in its lower end, cutting means on the lower end of the body adapted to make an annular cut and leave a core for reception by the opening, a. reciprocable shank in the body, a cutter on the shank operable to act on the core and retractible into said opening, a spring pressed hammer member in the body rotatable therewith, and parts on the hammer member and shank adapted to cooperate for the transmission of torque, said parts having surfaces adapted to cooperate to force the hammer member upwardly and releasable to cause impact of the member against the shank.

12. A well drill including a body to be rigidly attached to a drilling string to be rotated thereby, the body having an opening in its lower end, cutting means on the lower end of the body adapted to make an annular cut and leave a core for reception by the opening, a reciprocable shank in the body, a cutter on the shank operable to act on the core and retractible into said opening as the core is received in the opening, means urging the cutter downwardly, including a member in the body rotatable therewith and shiftable therein and adapted to engage the shank, and means controlling the cutter including cam parts on the member and shank.

13. A well drill including a body to be rigidly attacked to a drilling string to be rotated thereby and to move longitudinally therewith, the body having an opening in its lower end, cutting means on the lower end of the body adapted to make an annular cut and leave a core for reception by the opening, a reciprocable shank in the body, a cutter on the shank operable to act on the core and retractible into said opening, means urging the cutter downwardly, including a member in the body rotatable therewith and shiftable therein and adapted to engage the shank, means for conducting fluid through the body to discharge above the cutter, and means controlling the cutter including cam parts on the member and shank.

14. A well drill including a body to be rigidly attached to a drilling string to be rotated thereby and to move longitudinally therewith, the body having an opening in its lower end, cutting means on the lower end of the Vbody adapted to make an annular cut and leave a core for reception by the opening, a reciprocable shank in the body, a cutter on the shank operable to act on the core and retractible into said opening, an anvil part on the shank, a hammer member shiftable in the body and rotatable therewith and adapted to engage the anvil part, a spring acting on the hammer member to urge the shank and cutter downwardly, and cam parts on the hammer member and shank adapted to transmit torque and operable under heavy torque to move the hammer member upwardly and then release it for downward movement to bring it into impact with the hammer member.

l5. A well drill for use on a rotary drilling string including, a tubular body, means for rigidly connecting the body with the string, cutting means on the lower end of the body for making an annular cut and leaving a core for reception in the body, a cutter for destroying the core shiftable relative to the body to retract therein as the core is formed, a shank on the cutter, a hammer member in the body rotatable therewith and shiftable axially therein, the hammer member having a socket whose wall forms an impact surface for striking the shank, and cam means on the shank and member causing the member to strike the shank to actuate the cutter.

JOHN H. HOWARD. 

